How much water
does AI use?
The real numbers, why they disagree, and how GreenCube counts the water you save.
Your PC uses a fan. Not a cooling tower.
- 1
Cloud AI runs in data centres
They get hot, and many cool down by evaporating fresh water.
- 2
GreenCube runs on your PC
Your computer cools itself with a fan. No data-centre water is used for your question.
- 3
The app counts it
Every message on GreenCube is one that didn’t need that water: about 15 mL each.
It depends who you ask.
Sources: Google (2025) · UC Riverside, “Making AI Less Thirsty” (2023).
Two places it goes.
Cooling
Data centres get hot. Many cool down by evaporating fresh water, and that water doesn’t come back.
Electricity
Power plants use water too. Counting it can make the number around ten times bigger, which is why estimates disagree.
Where and when
A hot, dry place in summer uses far more water than a cold one in winter. Same question, different answer.
How GreenCube counts your water saved.
The app shows how much data-centre water you’ve saved. Slide to try it.
of data-centre water saved
We count 15 mL per message: the middle of UC Riverside’s 10 to 25 mL. With Google’s own number it would be about 60 times less, so treat it as an estimate. We only count data-centre cooling water: your PC still uses electricity, and that has its own footprint.
What actually reduces it.
Cooler places, reused water
Building data centres where it’s cold, and cooling them with water that gets reused instead of evaporated.
Cleaner electricity
Wind and solar use far less water than coal, gas or nuclear plants.
Smaller models, on devices you own
A model that fits on your PC needs no data-centre cooling at all. That’s GreenCube.
Quick answers.
How much water does one AI question use?
Between a few drops and a couple of tablespoons, depending on who measures. Google says 0.26 mL for a Gemini prompt; UC Riverside estimated about 10 to 25 mL per ChatGPT question.
Why do the numbers disagree so much?
Some only count the cooling water in the data centre; others also count the water used to make the electricity. Location and season change it too.
How does GreenCube count water saved?
15 mL for every message you send on GreenCube, the middle of UC Riverside’s range. It’s an estimate, and we say so in the app.
Does GreenCube use no water at all?
It uses no data-centre cooling water. Your PC still uses electricity, and making electricity uses some water.
Want the bigger picture? AI & the planet